What Happens to the Hot Air?

Learning Targets

  • Students will investigate changes in density due to the heating and cooling of gases.
  • Students will use a model to observe what happens to the air (smoke) when part of the box is heated and there is cooler air on the other side.

Success Criteria

  • I can analyze results from a physical model to explain why hot air rises and cold air sinks.
  • I can construct and defend a model of convection that explains why hot air rises and cold air sinks in terms of movement of air masses due to density differences.
  • I can apply a model to explain one cause of wind.

Questions to Ponder

  • What do you think would happen if a mass of cold air and hot air were next to each other?
  • How could you investigate this question?
  • What problems might you have in figuring out what is happening with the air?

Prediction

In this experiment we will use this special box. On one side we will have cold water and on the other side we will have hot rocks.

We will hold incense which will produce smoke above the cold water side.

Predict what will happen to the smoke.

Building toward Performance Expectation MS-PS1-4

Matter and Its Interactions

Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed.

Clarification Statement: Emphasis is on qualitative molecular-level models of solids, liquids, and gases to show that adding or removing thermal energy increases or decreases kinetic energy of the particles until a change of state occurs. Examples of models could include drawings and diagrams. Examples of particles could include molecules or inert atoms. Examples of pure substances could include water, carbon dioxide, and helium.

Building toward Performance Expectation MS-PS3-5

Energy

Construct, use, and present arguments to support the claim that when the kinetic energy of an object changes, energy is transferred to or from the object.

Clarification Statement: Examples of empirical evidence used in arguments could include an inventory or other represen- tation of the energy before and after the transfer in the form of temperature changes or motion of object. [Assessment Boundary: Assessment does not include calculations of energy.]